MOLLUSCS II. PROSOBRANCHIATA Paludestrina jenkinsi (Smith). — ventrosa (Mont.). Dead at Southport BUhynta tentaculata (Linn.) — leachli (Shepp.) Vivipara v'w'tfara (Linn.) Droylsden specimens, sparingly. Vivipara contecta (Millett) Valvata piscinalis (Mull.) — cristata, MuIl. Pomatias elegans (MuIl.). Carnforth Acicula lineata (Drap.). around Manchester ; Preston Neritina fluviatilis (Linn.) Between Grange and Fleetwood ; Grange ; B. PELECYPODA Dreissensia polymorpha (Pall.) Unio pictorum (Linn.) ■ — tumidus, Retz. — tnargaritifer (Linn.). Gibertson (Alder Collec- tion) ; River Lune at Caton (Dyson) Anodonta cygno'a (Linn.) Spharium rivicola (Leach) — comeum (Linn.) — ovale (F^r.) — kcustre (Mull.) Pisidium amnicum (MuIl.) — pusillum (Gtnel.). Near Silverdale, where also the variety P. obtusak, now held by some to be a distinct species, is found in a Shell- marl. Pisidium nitidum, Jenyns. — fontinale (Drap.). Common : the var. Hen- slomana has been found near Preston and near Manchester, and the variety P. pul- chellum occurs in a Shell-marl near Silver- dale. — milium (Held.). Bardsley and neighbour- hood 99
